In recent years, attempts are made to use fuel cells as power supplies for personal computers and mobile electronic devices such as cellular phones. Fuel cells make portable electronic devices usable for a long time without charging. Fuel cells are advantageous in that electric power can be generated by simply supplying a fuel and air and can be continuously generated by simply charging or replacing the fuel only. Therefore, if downsizing can be achieved, fuel cells can be said to be extremely effective for long time use of portable electronic devices.
Particularly, a direct methanol fuel cell (DMFC) is promising as power supply for small devises because the DMFC can be downsized and handling of a fuel is also easy compared with a hydrogen gas fuel.
Known as methods of supplying the DMFC with a fuel are a gas-supply-type DMFC in which a liquid fuel is vaporized and fed into a fuel cell by a blower and the like, a liquid-supply-type DMFC in which a liquid fuel is directly fed into a fuel cell by a pump, and an inner-vaporization-type DMFC in which a liquid fuel is vaporized inside a cell. Of these methods, the liquid-supply-type DMFC is known by its technology of connecting a fuel cell to a fuel tank through a tube. The foregoing technology is described in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2008-235243. Further, technology of providing a pump between a fuel cell and a fuel tank and connecting the fuel cell to the pump as well as the fuel tank to the pump is disclosed.
Since the fuel cell described above can be fed with a fuel by a pump when required, controllability of a fuel supply amount can be improved. However, there is a case that the fuel cell and the pump cannot be connected through a tube to prevent leakage of a fuel. Even if such a connection can be made to prevent leakage of a fuel, the fuel can leak for any reason, e.g., vibration and impact which act on the fuel cell may cause the tube to fall off or a connection part to be loosened or damaged. Further, if the tube is crushed, fuel feed may be interrupted.
Therefore, there are demands for a highly reliable fuel cell which prevents leakage of a fuel and interruption of fuel supply.